Kind of Stress.
2. Compression ...
3. Shear ......
4. Torsion (momenta! shear)
6. Bending (momenta! com-
pression and tension),..
7. Bending + Tension
8. Bending + Compression
9. Torsion + Bending
i o. Torsion -f Compression...
I Lifting rods, chains, bolts, ropes, boiler shells,
pipes and cylinders, boiler stays, flywheel
All short pillars. Oims-
Punching and shearing, rivets, pins, cotters,
coupling bolts, keys.
Short shafts, spiral springs.
Plate edges on rivets, cotter edges, and canti-
Beams, axles, boiler end plates, slide bars, teeth
Long pillars, boiler flues, ships' davits, con-
Long shafts, crank arms.
' Propeller shafts.
Tension Stress-Action.—Unit stress x area of section
will give total stress. Therefore :—
Load = Total stress.
W - ft a.
In the case of steam or water pressure the load is unit pressure x
area pressed upon, and
/tons x area of boiler end, or piston, in square ins. =/t a.
Of course/t may be either * breaking' or 'safe,' and W or p will
vary in like manner.
Example l.~Find safe load for following sections, at 5 tons per
•square inch, (i) 3 ins. dia, (2) 3 ins. dia. with f" cotterway. (3)
3" tube with 2" hole. (Eng. Exam., 1892.)